Vents are required in buildings to permit air exchange with the outside for dryers, bathroom and kitchen fans, and heating and cooling, among other reasons. Vent coverings prevent outside air from entering buildings, while permitting inside waste air to be exhausted to the outside. However, such vent coverings suffer wear and tear, and in time no longer seal the outside air out as well as when they were new, and need to be replaced. However, replacing a vent covering is difficult and not available to the average homeowner because of the complexity in making a seal with the vent duct aperture, and the danger that removing the old vent covering will pull the vent duct loose within the wall. This last situation is difficult to repair because the wall needs to be entered from the interior of the house, through the drywall. Typically a professional is required which can greatly increase costs and cause delays in the repair of the vent covering, leading to environmental inefficiency in the form of air leakage in the meantime.
Previous attempts have been made in order to address this problem such as U.S. Pat. No. 4,967,490 (Berger), which has louvers and a vent hood that appear to be replaceable should they malfunction, however, it is awkward changing each individual louver, and then setting a new hood atop the replaced louvers. There is no mechanism for facilitating this replacement and it is only by bending the plastic louvers that the new louvers fit in the recesses along the edges of the side walls of the vent.
U.S. Pat. No. 5,482,507 (Priest) describes a vent structure and separate masonry guide, which fits over the vent duct aperture. The masonry guide fits generally over the vent duct aperture, and a louvered portion fits within the masonry guide. The louvered portion is replaceable if defective, however the invention does not produce a seal with the duct opening, so as to be environmentally-insulating. As well, the louvered portion is not intended to be replaceable, and the screw holes used to mount the louvered portion would wear out in short order as it is replaced.
Accordingly, there is a need for an easy to use louvered vent hood which facilitates its own replacement as well as replacement of certain parts of the vent.